I checked the dump and I think I found a problem.
Could you please test a modified version of one avast! module to see if it makes any difference (that is, if the periodic crashing stops)?
To replace the module, the following needs to be done:
1. Download
this archive2. Disable avast! self-defense (by unchecking: Settings / Troubleshooting / Enable avast! self-defense module)
3. Navigate to avast! installation folder (by default, C:\Program Files\Avast Software\Avast) - e.g. in Windows Explorer, or any other file manager
4. Rename the file ashServ.dll to something else (e.g. ashServ2.dll)
5. Extract the content of the archive, downloaded in step 1, into the installation folder
6. Restart the avast! Antivirus service (or simply restart the machine)
7. Reenable the self-defense
Thanks!